CG LIMITS EXCEEDED FOR LNDG.

Narrative

I WAS CALLED AT HOME BY CREW SCHEDULING INFORMING ME THAT MY ORIGINAL TRIP WAS CANCELED AND THAT I WAS TO FERRY AN ACFT TO ORD. CREW SCHEDULER DID NOT KNOW THE REASON FOR THE FERRY. AT BOS OPS I PULLED PAPERWORK AND CALLED DISPATCH ABOUT THE LOW ARR FUEL AT ORD. INFORMED AT THAT TIME THAT THE ACFT HAD A MAINT PROB REQUIRING A SPOT MESSAGE. FUELER CAME INTO OPERATIONAL AREA TO DISCUSS CONFUSION OVER THE FUEL LOAD. WHILE AWAITING FOR A RIDE TO THE N RAMP WHERE THE ACFT WAS LOCATED - A MAINT TECH BRIEFLY OUTLINED THE RUDDER LIMITER SYS PROB (WEAK COILS AND PULL ROD ASSEMBLY FOR ME. AS WE WERE RUNNING LATE; 30 MINS TO TKOF) I ELECTED TO PROCEED TO THE ACFT AND RESOLVE THE FUEL LOAD THERE. I WAS PREOCCUPIED WITH FINDING OUT ABOUT THE RUDDER PROB AND ANY OPERATIONAL CONSIDERATIONS THAT APPLIED. UNDER THE TIME CONSTRAINTS OF THE DEP TIME I DID NOT FULLY EXPLORE ALL THE RAMIFICATIONS OF THE BALLAST FUEL THAT FINALLY WAS LOADED ABOARD THE ACFT. THE FO AND I DISCUSSED THE FUEL BURN SIT AFTER HE HAD TO INPUT THE FUEL LOAD INTO THE ACARS SECOND TIME. WE THEN REVISITED THE RUDDER PROB ONCE MORE BEFORE TOWING THE ACFT OUT FOR TAXI. THE FLT PROCEEDED NORMALLY UNTIL WE REALIZED THAT WE HAD NEGLECTED TO STOP THE CTR TANK FUEL BURN AT 5000 LBS AS WE HAD DISCUSSED. THE CTR TANK HAD BURNED DOWN TO APPROX 350 LBS AT THAT POINT. AS WE WERE IN THE INITIAL PORTION OF DSCNT TO ORD I ELECTED TO HOLD AT PIVOT INTXN IN ORDER TO CONTACT TECH SUPPORT THROUGH DFW DISPATCH. AFTER HOLDING FOR APPROX 20 MINS I WAS GIVEN SEVERAL RECOMMENDATIONS FOR OUR LNDG. WE FOLLOWED THE RECOMMENDATIONS AND LANDED THE ACFT ON RWY 22R WITHOUT FURTHER INCIDENT. HAD I NOT BEEN SO PREOCCUPIED WITH THE RUDDER PROB AND THE DEP TIME AND REVIEWED THE BALLAST FUEL PROCS THIS SIT MAY HAVE BEEN AVOIDED.